Pressure controlled switch



June 19, 1934. QWEGER E1- AL 1,963,864

PRESSURE CONTROLLED SWITCH Filed Nov. 2l, 1952 /A/Vf/VTORS.

Patented June 19, 1934 UNITED STATES PATENT GFFICE 1,963,864 PRESSURE ooN'rRoLLED SWITCH Application November 21, l1932,Serial No. 643,682.-

12 Claims. Y (Cl.'200-83) This invention relates to a pressure controlled switch and more particularly to that type of switch which is used for automatically controlling the pressure in a storage tank for liquid.

One object of the invention is to provide such a switch which will be simple in its construction, positive in its operation and which can be produced at a low cost.

A further object of the invention is to provide such a switch in which there will be little or no sparking when the contacts are opened or closed. Other objects of the invention will appear as the device is described in detail.

In the accompanying drawing Fig. 1 is a vertical section View taken through the switch and showing the switch in its open position; Fig. 2 ls a side elevation of the switch mechanism, partly broken away, and showing the switch closed; Fig. 3 is a plan view of the switch mechamism; Fig. 4 is a sectional detail view taken on the line 4-4 of Fig. 1; and Fig. 5 is an end View of the contact supporting members, partly in section.

In the drawing we have illustrated one embodiment of our invention but it will be understood that the mechanism may take various forms and may be arranged in various ways without departing from the spirit of the invention.

In that embodiment here illustrated the switch mechanism is enclosed within a casing which comprise a base 6 on which operating parts are mounted, and a removable housing '7 supported by the base. Mounted on the base and extending upwardly therefrom is a supporting-structure 8 here shown in the form of a bracket comprising two side plates, the lower ends of which are spaced apart and provided with flanges 9 by means of which they may be secured to the base. The rear edges of the bracket plates, that is the left hand edges as shown in the drawing, are substantially vertical and are provided with laterally extending ears 10 to which is rigidly secured a terminal plate 1l. rThe side plates of the bracket converge upwardly and their upper portions are spaced a short distance apart. In the present instance the bracket is formed from a single piece of sheet metal bent to the desired form and the upper edges of the two plates are connected at their rear portions by the transverse portion of the blank, as shown at 12. This upper or transverse portion of the bracket is cut away along the forward portion of the bracket so that the space between the two plates is open at its upper edge. The bracket is provided near its top with a forwardly extending portion 13, the

forwardly extending portions of the two plates having opposed vertical recesses 1'1 to form a guideway for an actuating member.

The actuating device may take various forms butas here shown it comprises a vertically movable rod or plunger 15 which is slidably mounted in the guideway in the forwardly projecting part 13 of the bracket. Any suitable pressure control'ed device may be employed for imparting movement to the actuating device and, as here shown, the base 6 is provided with an opening 16 in line with the guideway in the bracket, the base at the edge of the opening being curved upwardly, as shown at 17, so that the opening is surrounded by an upwardly tapered wall. 70. Rigidly secured to the base and beneath the opening 16 is a concave member 18 within which is formedfa pressure chamber across which extends a diaphragm 19. The concave member 18 has a screw threaded opening 20 to receive the upper 75 end of the pipe 21 by means of which the pressure chamber is connected with the storage tank within which the pressure is to be controlled. Mounted within the opening 16 and resting upon the diaphragm 19 is a cup-shaped member or plate 22 having a substantially vertical cylindrical wall slidably mounted in the tapered wall 17 which surrounds the opening. It will be noted that the surrounding wall 17 has a narrow contact with the cup-shaped member so that the latter may readily adjust itself in the opening. The actuating plunger 15 is secured at its lower end to the bottom of this cup-shaped member and is acted upon by a spring 23 which is confined between the part 13 of the bracket and a nut 24 screw threaded onto the lower portion of the plunger, and thus serves to resist the upward movement of the plunger by the pressure on the diaphragm. By adjusting the nut the amount of pressure required to impart movement to the plunger may be varied.

Supported above the base 6 are two movable members which support the switch contacts and which are mounted for movement in unison and for relative movement. The contact supporting members are so connected with the actuating device 15 that when that device moves in either direction the two contact supporting members will. move in unison therewith. Other means act upon one of the contact supporting members to 105 move the same with relation to the other contact v supporting member after the actuating device has moved a predetermined distance and thus cause the contacts to be moved to their open or closed positions, according to the direction in which the 110 ctuating device is moving. As here shown, these contact supporting members comprise two levers and 26. The lower lever 25, which is in the form of a fiat plate or stamping, is arranged between the two plates of the bracket and is pivotally mounted thereon, preferably by a pivot pin 27 spaced some distance from the rear end of the lever. The forward portion of this lower lever is downwardly offset, as shown at 28, and carries one or more contacts. As here shown, a cross bar 29, preferably of insulating material, is secured to the part 28 of the lever and carries near each end thereof a contact 30. Each contact is provided on the lower side of the cross bar with a. binding post 31, by means of which the contacts are connected with flexible conductors 32 which lead to terminals 33 on the terminal plate 11, each of these terminals being provided with a binding post 34 on the outer side of the terminal plate by means of which' it may be connected with a line conductor, not here shown. This lower lever 25 is connected at a point in front of its axis with the actuating device 15, the latter being preferably slotted to receive the lever and being connected thereto by a pivot pin 35. The upper contact supporting lever 25 is here shown as U-sh'aped in cross section with its open side racing downwardly and embracing the upper portion of the lever 25. The lever 26 is preferably mounted on a nxed support and on an axis adjacent to the axis of the lever 25 so that when pivotal movement is imparted simultaneously to the two levers there will be little or no relative movement of the cooperating contacts. As here shown, the rear portion of the lever 26 has its side walls extended downwardly on opposite sides of the bracket 8, as shown at 36, and these downwardly extending sides of the lever are connected with the bracket by the same pivot pin, 27, which connects the lever 25 to the bracket, the two levers being thus mounted for movement about a common axis either separately or in unison. The upper lever 26 also extends rearwardly beyond its axis and is provided with means cooperating with the lower lever to limit its movement with relation to that lever, this means being here shown as a set screw 38 adjustably mounted in the upper lever and engaging the rear end or tail of the lower lever. The upper lever 26 is also provided at its forward end with means for supporting one or more contacts, this means being here shown as a cross bar 42 having mounted near its opposite ends contacts 43 similar to the contacts 30 and arranged to cooperate therewith. These contacts 43 are connected by flexible conductors 44 with terminas 45 on the terminal plate ll.

A cross bar 39 is rigidly secured to the upper lever near the forward end thereof and connected with the opposite ends of this cross bar are springs 40 which extend rearwardly on opposte sides of the levers and are connected at their rear ends to iixed supports, here shown as lugs 41 extending forwardly from the ears 10 on the bracket. The lugs 4l are so arranged with relation to the cross bar 39 that the intermediate portions of the springs will be moved across the axis of the lever as these levers move from one position to the other. Hence the springs will tend to hold the upper lever in that position to which it has been moved, with relation to the lower lever, while the two levers move in unison and as soon as the two levers have moved far enough to carry the springs across the axis of the levers the springs will impart quick movetion to the lugs 41, when the switch is in its open position, may oe varied and the amount of movement of the actuating device necessary to move the springs across the axis 27 thus altered.

When the switch is closed the parts are in the position shown in Fig. 2 and upward movement imparted to the actuating device 15 w.ll move the two levers in unison about their common axis, due to the fact that the upper contacts are resting upon the lower contacts. When the actuating device has moved a predetermined distance the springs will be carried across the axis of the levers and the upper lever will be moved about its ax's, relative to the lower lever, thus moving the parts to the position shown in Fig. 1 and opening the contacts. When the pressure on the d'aphragm is decreased the actuating device may be moved downwardly by the spring 23 and the two levers will move in unison therewith, due to the engagement of the set screw 38 with the tail of the lower lever. This movement will continue until the springs again cross the axis of the levers when the springs will again move the lever 26 its axis with relation to the lower leve i 25 to close the contacts.

It will be apparent that the springs 40 act upon the upper lever with a snap action and serve to qu'ckly move the upper contacts into and out of c gagement with the lower contacts, but a still more rapid separation of the contacts may be secured by providing for a limited movement of "he upper lever with relation to the contacts supported thereby, so that these upper contacts will remain in engagement with the lower contacts during the initial upward movement of the lever and will be picked up by the lever after the latter has gained speed and thus very quickly moved out of engagement with the lower contacts. In the present construction the walls ci the 'el-shaped lever 26 are provided with openings through which the cross bar 42 extends and these openings are of a vertical length slightly greater than the thickness of the bar so that the latter has a limited up and down movement with relation to the lever. tacts are closed springs 40 will move the for ward end of the lever 26 to the limit of its movement and the lower edges of the openings will be out of engagement with the cross bar 42 and the latter will not be engaged thereby until after initial movement has been imparted to the lever. If desired, a weight 46 may be applied to the cross bar to resist the upward movement thereof and hold the upper contacts rmly in engagement Cir with the lower contacts until the lower edges of the openings have engaged the cross bar.

By reason of the construction above descr'bed it wlll be apparent that both the upper and lower contacts move in unison during the rise and fall of the actuating device due to increasing or decreasing the pressure on the diaphragm and that the relative positions of the contacts is not affected until practically the end of the movement of the actuating device, at which time the upper contacts are quickly actuated to open or close the circuit. The major parts of the apparatus -re of such a character that they may be formed from sheet metal stampings and may be quickly and easily assembled, thereby enabling the switch to be produced at a very low cost.

The simplicity of the apparatus and the arrangement of parts is such that there is very little likelihood of the parts becoming disarranged or being rendered inoperative in service.

While we have shown and described oneembodiment of our invention we wish it to be understood that we do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described our invention what we claim as new and desire to secure by Letters Patent, is:

1. In a pressure controlled switch, two contact supporting members pivotally mounted on substantially coincident axes, a pressure controlled actuating device acting on said members to move them in unison about said axes, and means controlled by the positions of said members to move one of said members about its axis with relation to the other member when the two members have been moved in unison to predetermined positions.

2. In a pressure controlled switch,a supporting structure, a contact supporting lever pivotally mounted on said structure, a pressure controlled actuating device operatively connected with said lever, a second contact supporting lever pivotally mounted on said structure on an axis substantially coincident with the axis of the rst mentioned lever, and means for causing said second lever to move with said first mentioned lever and in substantially fixed relation thereto during the initial movement of said actuating device and to cause said second lever to be moved with relation to said first mentioned lever when said actuating device has been moved a predetermined distance.

3. In a pressure controlled switch, a supporting structure, two contact supporting levers pivotally mounted on said structure on a common axis, a pressure controlled actuating device operatively connected with one of said levers, said levers having means to cause the other lever to move in unison with the rst mentionedv lever during the initial movement of said actuating device, and a spring connected with said other lever on one side of its axis and with said supporting structure on the other side of said axis and arranged to be moved across said axis by the movement of said levers in unison.

4. In a pressure controlled switch, a supporting structure, two contact supporting levers pivotally mounted on said structure on a common axis between the ends thereof, one of said levers being movable with relation to the other lever, contacts carried by said levers on one side of said axis and serving to limit the movement of said relatively movable lever in one direction, said relatively movable lever having a part to engage said other lever on the other side of said axis and limit the relative movement thereof in the other direction, a pressure controlled actuating device operatively connected with said other lever, and spring means acting on said relatively movable lever to move the same with relation to said other lever when said actuating device has moved a predetermined distance.

5. In a pressure controlled switch, a base, a pressure controlled device carried by said base and comprising a plunger, a supporting structure mounted on said base and having a guideway for J said plunger, a lever pivotally mounted on said supporting structure and operatively connected with said plunger, a second lever pivotally mounted on said supporting structure on an axis substantially coincident with the axis of said rst mentioned lever, contacts carried by the respective levers and movable into and out of engagement by the movement of said second lever with relation to said rst mentioned lever, and means including a spring acting on said second lever to cause the same to move with and in substantially fixed relation to said first mentioned lever during the initial movement of said plunger in either direction and to cause said second lever to move with relation to the first mentioned lever when said plunger has moved a predetermined distance.

6. In a pressure controlled switch, a base, a pressure controlled device carried by said base and comprising a plunger, a supporting structure mounted on said base and having a guideway for said plunger, a lever pivotally mounted on said supporting structure and operatively connected with said plunger, a second lever substantially U-shaped in cross section, embracing the upper portion of the iirst mentioned lever and pivotally mounted on said supporting structure on an axis substantially coincident with the axis'of the rst mentioned lever, contacts carried by the respective levers and movable into and out of engagement by the movement of said second lever with relation to said rst mentioned lever, means including a spring acting on said second lever to cause the same to move with and in substantially iixed relation to said rst mentioned lever during the initial movement of said plunger in either. direction and to cause said second lever to move with relation to said first mentioned lever when said plunger has moved a predetermined distance, and adjustable means to time the movement of said second lever of said spring means with relation to the distance traveled by said spring.

7. In a pressure controlled switch, a base having an opening, an upwardly curved wall surrounding said opening and a pressure chamber below said opening, a diaphragm in said pressure chamber, a cup-shaped member arranged in said opening, resting upon said diaphragm and guided by said wall, a plunger connected with said cupshaped member for movement therewith, a supporting structure carried by said base and having a guideway for said plunger, contact supporting levers pivotally mounted on said supporting structure, one of said levers being operatively connected with said plunger, and means acting on the other lever to cause the same to move with the rst mentioned lever in substantially xed relation thereto during the initial movement of said plunger and to move relatively to said first mentioned lever when said' plunger has moved a predetermined distance.

8. In a pressure controlled switch, two levers pivotally mounted on a common axis and arranged one above the other, a pressure controlled actuating device operatively connected with the lower lever, means acting on the upper lever to cause the same to move with said lower lever during the initial movement of said actuating device and to move with relation to said lower lever when the latter has been moved a predetermined distance, a contact carried by said lower lever, said upper lever having a transverse opening, a member mounted in said opening for up and down movement with relation to said upper lever, and a contact carried by said member.

9. In a switch of the character described, a base, an upright structure mounted on said base, a contact supporting lever pivotally mounted on said structure and extending substantially parallel with said base, an actuating device mounted on said base and comprising a movable part extending transversely to said lever and pivotally connected therewith at a point spaced from the pivotal axis of said lever, a second contact supporting lever pivotally mounted on said structure and extending substantially parallel with the rst mentioned lever, said levers having cooperating parts to cause them to move in unison during the initial movement of said actuating device, and means acting on said second lever to move the same with relation to the rst mentioned lever when a predetermined movement has been imparted to both levers by said actuating device.

l0. In a switch or" the character described, a base, an upright structure mounted on said base, a contact supporting lever pivo'tally mounted on said structure and extending substantially parallel with said base, an actuating device mounted on said base and comprising a movable part extending trai'lsversely to said lever and pivotally connected therewith at a point spaced from the pivotal axis of said lever, a second contact supporting lever plvotally mounted on said structure and extending substantially parallel with the rst mentioned lever, said levers having cooperating parts to cause them to move in unison during the initial movement of said actuating device, a spring connected with said structure and said second lever on opposite sides of the pivotal axis of the lever and arranged to move across said axis and move said second lever with relation to the iirst mentioned lever when a predetermined movement has been imparted to both levers by said actuating device.

ll. In a switch of the character described, a base, an upright structure mounted on said base, a lever pivotally mounted between its ends on said structure, extending substantially parallel with said base, an actuating device mounted on said base and having a movable part extending transversely to said lever and pivotally connected therewith at a point spaced from the pivotal axis of said lever, a second lever pivctally mounted between its ends on said structure on an axis adjacent to the axis of the rst mentioned lever and extending substantially parallel with the first mentioned lever, cooperating contacts carried by said lever on one side of their axes and adapted to cause said levers to move in unison during the initial movement of said actuating device in one direction, said levers having cooperating parts on the other side of their axes to cause them to move in unison during the initial movement of the actuating device in the other direction, and a spring connected with said structure and with said second lever on opposite sides of the pivotal axis of the latter and arranged to move across said pivotal axis and to move said second lever with relation to the iirst mentioned lever when both levers have been moved a predetermined distance by said actuating device.

l2. In a switch of the char eter deicribed, a base, an upright structure mounted on said base, a contact supporting lever pivotally mounted on said structure and extending substantially parallel with said base, a second contact supporting lever pivotally mounted on said structure en an axis adjacent to the pivotal axis of the iirst mentions lever and extending substantially parallel with said first mentioned lever, an actuating device having a part extending transversely to the rst mentioned lever and pivotally connected therewith at a point spaced from the axis of said first mentioned lever, said structure having means adjacent to said lever for guiding said part or said actuating device, said levers having cooperating parts to cause them to move in unison during the initial movement of said actuating device in either direction, and a spring connected with said structure and with said second lever on opposite sides of the pivotal axis of the latter and arranged to move across said axis and move said second lever with relation to the iii-st mentioned lever when both levers have been moved a predetermined distance by said actuating device.

LEO OWEGER. WILLIAM G. SIPPLE. 

